Concerning the period of the Creation as recorded in the book of Genesis in the Old Testament of the bible, it reads, "Thus the heavens and the earth were finished, and all the host of them. And on the seventh day God ended his work which he had made; and he rested on the seventh day from all his work which he had made." Genesis 2:1-2
To elaborate on the 7 days of Creation, the apostle Peter in the New Testament taught "...be not ignorant of this one thing, that one day is with the Lord as a thousand years, and a thousand years as one day." 2 Peter 3:8
If 1 day with God is 1,000 earth-years and 1 year is 365 days then -
365 God days or 1 God year is 365,000 earth-years;
1,000 God years is 365,000,000 earth years;
7,000 God years is 2,555,000,000 earth years.
Returning to Peter's teachings, "one day is with the Lord as a thousand years, and a thousand years as one day." In the second part of Peters statement, the 7,000 God-years can then be considered 7 days.
In addition to this the Times and Seasons teaches: "When the house of Israel begin to come into the glorious mysteries of the kingdom, and find that Jesus Christ, whose goings forth, as the prophets said, have been from of old, from eternity; and that eternity, agreeably to the records found in the catacombs of Egypt, has been going on in this system, (not this world) almost two thousand five hundred and fifty five millions of years; and to know at the same time, that deists, geologists and others are trying to prove that matter must have existed hundreds of thousands of years; -it almost tempts the flesh to fly to God, or muster faith like Enoch to be translated and see and know as we are seen and known!" (Times and Seasons vol. 5, pg 758)